The opinion of the court was delivered by: GALSTON
This is a patent infringement suit in which infringement is alleged of letters patent No. 1,854,600, granted April 19, 1932, to Fritz Pollak and Alfons Ostersetzer, for an improvement in a method for making phenol-formaldehyde condensation products, and for the product itself. Claims 1, 2, 3, and 5, all method claims, are in issue. The usual defenses of invalidity and noninfringement are asserted.
The specification as originally filed was found objectionable in form and content by the Examiner and led to several requests on the part of the Examiner for clarification. He finally demanded that "idiomatic English be employed." In its present form it presents a description of an important invention. The art is one which has been made known to the public through the so-called "Bakelite" products. Stated briefly the advance claimed by the inventors of the patent in suit is that the products made pursuant to the processes described are workable on the lathe or the like and are not brittle as were the products of the prior art.
Phenol is the chemical name for carbolic acid which ordinarily is found in the form of crystals. Commercial formaldehyde is sold in the form of a solution in water.
Phenol and formaldehyde were long used in making condensation products and the use of an alkali as a catalyst was also well known. Thus no novelty is claimed in the materials used in the process, nor is it contended that there is any novelty in the proportions suggested. The novelty has to do with a process which produces a novel physical structure and when narrowed down to the ultimate distinction has to do with the dispersion of water in the process.
In the earlier art the materials were of the Bakelite type of transparent ambers. The process involved drying over a long period of time and eliminated substantially all the water from the structure of the product.The result was a material very hard and very brittle. The object of the invention of the patent is obtained by keeping water in minute dispersion in the final product. The product of the patent can be worked on a machine such as a lathe, which it is claimed could not be done with the products of the prior art. We have then the anomalous situation of two products chemically identical but physically different, resulting from a difference of process of production.
The novelty is referred to in the specification in the following terms:
"The inventors have been successful in producing final products of the said reaction, which have the structure of true gels, as they include demonstrate capillarities. The artificial material made according to this invention has, in comparison with the known phenol-formaldehyde condensation products, the advantage that they can more easily be worked."
The inventors explain that in order to obtain these machine-workable products by the known reaction of formaldehyde upon phenol, the condensation products must be in a state of extremely fine dispersion with a slight degree of hydration, and must be stable. They found first that it is necessary to enlarge the molecule of the phenol-formaldehyde condensation products. This is effected by using larger quantities of formaldehyde than were theretofore usual. The inventors say that the most favorable results were obtained at the ratio of one molecule of phenol to about two and a half of formaldehyde.
The next step is to bring the condensation products having such chemical constitution to a state of colloidal dispersion.
The specification points out how this colloidal dispersion can be best obtained:
"This is preferably achieved by starting from systems of highest dispersion, that is to say from totally or partly molecular solutions, and by reducing the degree of dispersion down to the colloidal dispersion according to the principle of the colloid-chemical 'condensation method.'"
The third step is the conversion of this sol to a gel:
"The colloidal solution of a hydrophilic condensation product thus obtained is a clear sol, from which also on cooling no resin is precipitated, but which on the contrary in the course of a slowly proceeding concentration, sets to a true jelly by including the dispersion medium still present, namely the water."
The resultant jelly product is then hardened by heat, and the final product a dry and hard gel, the pores of which contain particles of water of colloidal size, is obtained.
The technical features of the art were explained by plaintiff's expert, Dr. Neville. It seems that in the course of the phenol-formaldehyde reaction, when equal mols of the material are used with a small amount of condensation agent, when they are first mixed they form a single phase, homogeneous solution. As the reaction continues, an insoluble product is formed which separates as a lower layer. This lower layer consists of phenol and formaldehyde. The upper layer consists of water with unreacted products dissolved in it.
Dr. Neville explained that gels such as the inventors sought as the final stage are produced from sols, i.e., colloidal dispersions. A sol is a liquid comprising water and a hydrophilic substance present in the form of particles which are larger than molecules but not large enough to be visible even under the microscope. Soap and gelatine, for example, dissolve with water to form more viscous liquids, and are illustrations of sols. Now the gels which result from sols are produced when the particles in a sol change so as to develop a definite structure while still remaining hydrophilic, so that no visible separation takes place. The essential condition in the change from the sol to the gel structure is that the hydrophilic substance forming part of the sol be changed prior to any change which renders the material positively hydrophobic, so that water is precipitated, but owing to the previously formed structure of the mass, i.e., the gel, the water is in the form of exceedingly small droplets.
A number of photomicrographs were introduced, showing the fine microscopic structure of those capillary cells.
The plaintiff, through Dr. Neville, presented studies to prove statements in the patent that it was advantageous to increase the ratio of formaldehyde to phenol to produce the two-phase system. As a result of his tests, he concluded that the ratio of phenol to formaldehyde should be in excess of the 1-1 ratio, perhaps in the ratio of 2 mols of formaldehyde to 1 of phenol up to a ratio of 3 mols of formaldehyde to one of phenol, and that the product showing the best commercial characteristics lies perhaps in the ratio of 2.25 to 2.5. Since, however, the plaintiff has disclaimed any novelty based on the determination of that ratio by the inventors, it will not be necessary to dwell on the subject further.
The commercial adaptation of the process of the plaintiff indicates that phenol and formaldehyde are brought together in a ratio of 1 to 2.35. They are condensed in the presence of an alkali such as caustic soda, 3 per cent. being used. The reaction takes place at a temperature of 65 degrees centigrade or thereabouts, and is continued for about two and a half hours. During that time resin has been substantially formed. The water is removed from the solution as a by-product in the reaction by a vacuum distillation. During that time the temperature falls to about 35 or 40 degrees centigrade, and in order to compensate for the reduction, heat is applied to the reaction vessel. This is continued for about eight hours, until the resin is brought back to a temperature of about 60 degrees centigrade. Acid is then added to neutralize the caustic soda and to give it a slightly acid reaction. After the addition of the acid, the vacuum is continued for the purpose of taking off a considerable quantity of water. Thompson, the plaintiff's chemist, said:
"The final stages of the vacuum distillation are watched carefully and samples are taken periodically to determine the water content.
"Now, we prefer to do this by taking a sample of resin from the kettle and placing it on a knife in cold water. That resin congeals, and if it is hard when pressed between the thumb and forefinger, we consider it finished.
"This comes after some experience, and the man can tell very closely just when the reaction has reached the end point.
"It is comparable, of course, to the manufacture of candy from a sugary syrup. There, of course, the water is taken off in vacuum until such time as a sample taken from that sugar becomes hard and brittle in cold water. Or probably a better example would be the manufacture of current jelly. If a sample is taken off periodically, we find that -- at the end stage at which enough water has been removed -- that the sample congeals in cold water and the jelly at that stage is ready to cast.
"Now, the casting of our resin, after it has reached the end point and sufficient water has been removed, is accomplished, as one skilled in the art will understand, as, for example, casting into an open mold, either a glass or metal mold.
"If more translucent products are desired, we prefer to add glycerme. This gives us a wider range, as far as color is concerned, and enables better uniformity.
"After the resin has been cast into molds, it is then put into ovens at about 75 degrees centigrade, and the heat is maintained at that temperature, plus or minus a few degrees, until the resin has been fully hardened to the infusible, insoluble stage, but during the first curing the resin changes from a transparent product, as you see in that one bottle there -- that product -- to a gel which remains transparent for possibly 20 -- 15, 20 hours and then as heat progresses this gel eventually is converted to the hard, infusible, insoluble product."
The question is then whether the process as thus used by the plaintiff is a departure from the teachings of the patent, or whether the patent is in its disclosures insufficient to apprise ...